1. Field of the Invention
The present invention relates to a solid-state imaging apparatus, a method for manufacturing the same, and a camera.
2. Description of the Related Art
A back-side illumination solid-state imaging apparatus includes a substrate including a photoelectric conversion portion, an optical system arranged on the back side of the substrate, and a structure arranged on the front side of the substrate and including a wiring layer and an interlayer insulation film.
A light-shielding member having an opening on a photoelectric conversion portion is provided on the back side of the substrate in order to prevent leakage of light between adjacent pixels which causes a color mixture. The light-shielding member can be made of, for example, a light-shielding material such as a metal material. The optical system can include, in addition to a microlens, an inner lens arranged between the photoelectric conversion portion and the microlens to improve light sensitivity. Japanese Patent Laid-Open No. 2011-135100 describes a back-side illumination solid-state imaging apparatus which uses an inner-layer lens and a light-shielding film.
An example of the arrangement of a back-side illumination solid-state imaging apparatus ID which includes a substrate SUB including photoelectric conversion portions PD, an optical system OP including microlenses ML and inner lenses IL, and a metal pattern PM having openings O will be described with reference to FIGS. 1A and 1B. FIG. 1A is a schematic view showing the upper surface of the metal pattern PM of the solid-state imaging apparatus ID. FIG. 1B is a schematic view showing the sectional structure of the solid-state imaging apparatus ID taken along a cut line A-A′.
A lens member which forms each inner lens IL can be provided on the metal pattern PM to cover the metal pattern PM. When light L enters the upper surface of the metal pattern PM from the microlens ML side, as illustrated in FIG. 1B, multiple reflection can occur inside the lens member which forms each inner lens IL. The quality of an image obtained by the solid-state imaging apparatus ID can be deteriorated by entry of the light L owing to the multiple reflection into the photoelectric conversion portion PD.
As shown in FIG. 1A, in the upper surface of the metal pattern PM, a distance D1 between the openings O in a cut line A-A′ direction is larger than a distance D2 between the openings O in a horizontal direction. The influence of the above-described multiple reflection is attributed, for the most part, to multiple reflection which has occurred in the portion of the distance D2.
Japanese Patent Laid-Open No. 2009-272650 discloses a front-side illumination solid-state imaging apparatus. In contrast to a front-side illumination structure, the structure which includes the wiring layer and the interlayer insulation film is not arranged between the substrate and the optical system in a back-side illumination structure. Accordingly, the back-side illumination structure is smaller than the front-side illumination structure in terms of a distance between a metal light-shielding member covering the lens member which forms each inner lens and the substrate including the photoelectric conversion portions, and is susceptible to the light owing to the above-described multiple reflection.